Ribbon ink composition



Patented May 30, 1939 UNITED STATES 2,160,511 RIBBON INK COMPOSITIONSamuel A. Neidich, Burlington, N. J.

No Drawing. Application December 22, 1936, Serial No. 117,182

8 Claims. (c1. 134-313 This invention relates to ink compositions, andwill be explained with particular relation to the manufacture of inksfor coating, saturating or impregnating the ribbons of typewriting andother printing and manifolding mechad msms.

There are a large number of formulas for the compounding of inks forsaturating typewriting machine ribbons, but irrespective of the formulaused, other than that set forth in my co-pending application, Serial No.51,202 filed November 23, 1935, on which the present invention is animprovement, the ribbons treated with inks prepared according to theformulas of commerce, deteriorate with age, or exposure to light or air,

or to variations in temperature.

Typewriting ribbons subjected to such exposure, or on account of age,dry out due to chemical changes in the fluid content of the inks, theimprint becomes paler, the oil content present in all former typewritingribbon inks, so far as I am aware, becomes rancid and sticky,- and thecharacteristics of the ingredients change, all to the end that theribbons fail to give. satisfaction r in use, and their length of serviceis shortened.

' Because of these well-known disadvantages,

some of which are apparently the result of oxidation of the inkingredients, it is customary for dealers in typewriting machine ribbons,for instance, to dispose of their oldest stock of this commodity as soonas possible, to avoid the losses otherwise sustained by spoilage.

My invention, like that disclosed in my co pending application, isdesigned to materially delay, if not wholly eliminate, the occurrence ofthe foregoing ills to which typewriting ribbons are subject through ageandexposure, the present invention distinguishing from my priorinvention by the use of anovel ingredient for inks, whereby to securethe desired results in a better 40 manner, and retain-the naturalcharacteristics of the inks so compounded over a longer period thanheretofore.

In the study, manufacture and testing of ribbon ink formulae embodyingas one ingredient tri-cresyl phosphate, according to my prior invention,I was impressed with the need for another definite chemical ingredientas a substitute for the oleic acid, red oil or other similaroil-miscible acid heretofore used as a solvent for the aniline or basiccolor base. Such substitute should be of an oily nature, with a lowsurface tension, and which would not itself change in characteristicsthrough a long period of time, 55 when used in connection with the otheringredients of a ribbon ink. Such ingredient should not only improve theink compound, but also eliminate a fruitful cause for the aforementionedills to which typewriting ribbons were subject.

Continued consideration of this problem resulted in the discovery thatthe use of diglycol laurate, in combination with tri-cresyl phosphate,and the usual coloring and toning ingredients produced a much improvedink wherein the advantages attained by the ink formula of my formerapplication, were greatly enhanced.

Diglycol laurate, asto its physical properties, is a thin, oily-feelingliquid, having both a low surface tension and low viscosity.

Diglycol laurate apparently possesses a 15 slightly acid reaction whichconstitutes it a per fect solvent for color bases, and it can be reliedupon to a far greater extent than red oil or oleic acid, for freedomfrom deterioration through longer periods of time, and for uniformity ofproduct.

Thus, I have found that diiferent lots of oleic acid contain residualstearic acid in varying amounts, and as a consequence, ribbon inksincluding this part as a majoringredient vary materially from an exactstandard, and are not uniform.

An example of one formula for black ribbon inks compounded in accordancewith this invention, contains the following ingredients and protions:

. Parts Carbon black 6 Tri-cresyl phosphate l5 Nigrosine base .9Diglycol laurate; 15

Obviously, the proportions of the above ingreclients may be variedsomewhat without materially affecting the compound.

Also it is obvious thatif a ribbon ink of another color than black is tobe compounded, the proper pigment and toning agent would be substitutedfor the carbon black and the Nigrosine base. For instance, if a purplerecord is desired, a purple lake would be substituted for the carbonblack of the above sample formula, and Methyl Violet base substitutedfor the Nigrosine base; or for a blue record, a Prussian or "Milori Bluepigment would be ued in place of the carbon black, and a Victoria Bluetoning agent used in place of the Nigrosine base.

It will be understood that in making these substitutions for obtainingdifferent colored ribbon inks, slight changes may be made in theparticular proportions heretofore stated, to obtain the best compound.

The ingredients are thoroughly mixed and ground in any convenient millaccording to wellknown methods, the process of compounding forming nopart of the present invention.

From actual tests made from many ribbons treated with inks compounded inaccordance with the foregoing formula, I have proven that ribbon inksincluding diglycol laurate as an ingredient give a more intense andsharper write than that made with ribbons treated with a variety of inkswhich do not include diglycol laurate as an ingredient. Also thedurability and life of the ribbon as well as the speed of recuperation,that is, the transfer of ink by capillary action from the unused to theused areas of the ribbons, are all greatly increased.

Furthermore, it is evident from an inspection of the typical formula,that the compounded ribbon ink is wholly free from oil.

The aniline color bases or toning agents are treated with diglycollaurate in place of oleic acid, which acts as a solvent therefor, theresult being a strong, oily solution of the particular color readilymiscible with the pigment and tri-cresyl phosphate, and enabling acomplete dispersion of the pigment uniformly throughout the fluid whilebeing compounded.

One attribute possessed by the herein disclosed invention in ribboninks, and one which I believe to be wholly novel, so far as I am aware,is its ability to effect a write on the sheets, laminated or otherwise,used in the comparatively recently developed process of lithographingfrom non-metallic lithographic plates, so as to enable a satisfactorylithograph image to be made therefrom.

In this process, it has been attempted, heretofore without success, totypewrite the material to be lithographed, directly upon a non-metalliclithograph plate through the use of the ordinary ribbons of commerce. Bythe use of ribbons treated witha ribbon ink compounded in accordancewith the herein-described ingredients, most satisfactory lithographicimpressions were made directly from the typewriting machine onto thenon-metallic or paper plate without difliculty.

The tricresyl phosphate is used in such an amount as to serve as avehicle for the finely ground pigment suspended therein, and thediglycol laurate is used for the purpose; among others, of dissolvingthe basic color base, and for rendering the ink suitable for use informing lithographic images on non-metallic plates from which a farlarger number of reproductions can be made than heretofore with otherinks.

The diglycol laurate is also used in quantity suflicient to serve as apart vehicle for the pigment.

What is claimed as new, is:

l. A ribbon ink, the ingredients of which inelude a finely dividedpigment suspended in tricresyl phosphate, and a basic color basedissolved in diglycol laurate.

2. A ribbon ink composed of approximately 15 parts of tricresylphosphate; 6 parts of a pigment of the desired color; 9 parts of atoning base to intensify the color of the pigment; and 15 parts ofdiglycol laurate as a solvent for the toning base.

3. A ribbon ink for forming lithographic images on a non-metallic plate,including as ingredients, diglycol laurate to function as a solvent fora dye base, and tricresyl phosphate in an amount suflicient to functionas a vehicle for a pigment of the desired color, and dyed with the baseof a basic dye stuff soluble in the diglycol laurate.

4. An ink for forming lithographic images on a non-metallic plate, whichink resists the chemical treatment usual in the lithographing art torender the uninked surface of the plate ink-repellant and waterabsorbent, the ink composed of tricresyl phosphate; a pigment suspendedtherein; and the base of a basic dye stuff dissolved in diglycol lauratewhich has a slight acid reaction.

5. An ink for use in forming lithographic images on non-metalliclithograph plates, comprising a pigment; tricresyl phosphate in quantitysufficient to serve as a vehicle for the pigment,

and being a viscous non-drying fluid having luo bricity and resistant todeterioration by exposure to atmospheric changes, heat, light andhumidity; a suitable basic color base; and diglycol laurate in quantitysufficient to serve as a solvent for the dye base, and also functioningto increase the number of reproductions obtainable from a non-metalliclithographic plate, and as a part vehicle for the pigment.

6. A ribbon ink compound containing finely ground pigment of the desiredcolor; tricresyl phosphate, as a non-drying vehicle, in an amount toserve as a carrier for the pigment suspended therein; and a basic colorbase dissolved in diglycol laurate.

7. A ribbon ink compound containing a finely ground pigment of thedesired color; tricresyl phosphate, as an oilless vehicle, in an amountsufficient to function as a carrier for the pigment suspended therein;and a toning basic color base dissolved in diglycol laurate.

8. An oilless ribbon ink comprising a finely divided pigment; tricresylphosphate, as a nondrying, oilless vehicle, in an amount suflicient tofunction as a carrier for the pigment suspended therein; and modified incolor by the addition of

